Library 

OF  THE 


University  of  Nortb  Carolina 

This  book  was  presented  by 


'm 


July,  1923 


Extension  Circular  No.  137 


IK 


Vi,', 

B  ! 


N.  C.  AGRICULTURAL  EXTENSION  SERVICE 


OF  THE 


STATE  COLLEGE  AND 

STATE  DEPARTMENT  OF  AGRICULTURE  AND 

U.  S.  DEPARTMENT  OF  AGRICULTURE  COOPERATING 


B.  W.  KILGORE,  Director 

RALEIGH 


DUST-POISON  METHOD  FOR 
CONTROL  OF  BOLL  WEEVIL 


DISTRIBUTED  IN 


FURTHERANCE  OF  THE  ACTS  OF  CONGRESS  OF  MAY  8  AND  JUNE  30,  1914 


CONTENTS 


PAGE 

introduction  .  3 

Suggestions  for  1923  (Place  orders  early) .  4 

Operations  in  1922  (Discussion) .  5 

Table  of  Results — comparative  tests  (with  comment) .  6 

Testimony  of  Farmers  (comment)  .  T 

Chief  Difficulties  .  9 

Rains  . 9 

The  Night,  Work .  9 

Breakage  and  Wear  of  Machines .  10 

Regulating  Amount  Poison  Per  Acre .  10 

When  to  Begin  to  Dust . .  10 

Machinery  for  Cotton  Dusting  (Types) .  12 

Equipping  with  Dusting  Machines .  14 

“How  Many  Acres  Shall  I  Dust?” .  18 

Important  Points  to  Observe — or  Avoid .  18 

Dusting  Protects  But  Does  Not  “Make”  a  Crop .  18 

Study  Pays  .  19 

Follow  Directions  . 19 

Precaution  Against  Possible  Danger .  19 

Don’t  Be  Too  Uneasy  About  Early  Weevils .  19 

How  Arrange  Nozzles  for  Dusting . . .  20 

How  to  Poison  (The  Specific  Guiding  Directions) .  20 

Tests  by  Virginia-Carolina  Chemical  Company .  21 

(Results  of  237  tests  in  four  states) 

Final  Remarks  .  22 


DUST-POISON  METHOD  FOR  CONTROL  OF  BOLL  WEEVIL 


By  Franklin  Sherman,  Chief  in  Entomology, 

and 

W.  Bruce  Mabee,  Assistant  in  Extension  Entomology 


INTRODUCTION 

The  calcium-arsenate  dust-poison  method  for  control  of  the  boll 
weevil  was  developed  mainly  by  the  United  States  Bureau  of  Ento¬ 
mology,  chiefly  by  Mr.  B.  B.  Coad  and  his  associates  at  the  Delta 
Laboratory,  Tallulah,  La.  It  is  explained  in  Farmers  Bulletin  1262  of 
United  States  Department  of  Agriculture,  Washington,  D.  C.,  copies  of 
which  can  be  had  from  Washington  or  from  county  agents.  It  is  also 
explained  in  Circular  124  of  the  North  Carolina  Agricultural  Extension 
Service,  Baleigh,  N.  C.,  copies  of  which  may  be  had  from  county  agents 
or  by  application  to  Baleigh. 

.  The  present  circular  shows  results  secured  from  this  method  in 
southern  counties  of  North  Carolina  in  1922,  in  tests  directed  by  the 
North  Carolina  Division  of  Entomology  of  the  North  Carolina  State 
College  and  Department  of  Agriculture,  gives  testimony  of  farmers,  dis¬ 
cusses  the  chief  difficulties  encountered,  and  is  intended  to  make  the 
matter  so  plain  that  any  county  agent  or  any  studious  farmer  can 
proceed  with  even  greater  assurance  than  he  could  derive  from  the  other 
two  publications  already  mentioned. 

At  meeting  of  Southern  Agricultural  Workers  at  Memphis,  Tenn.,  in 
February,  1923,  a  committee  of  experienced  men  was  appointed  to  sum¬ 
marize,  condense  and  harmonize  the  facts  of  boll-weevil  poisoning  and 
control  problems. 

This  committee  represented  veteran  experience  with  boll  weevil,  with 
agricultural  work,  and  with  the  importance  of  being  accur  ate  and  safe. 
The  following  quotations  from  their  report  are  important  at  this  time 

in  this  connection : 


va 

N 
W 
n t 


“Of  the  various  methods  of  control  involving  the  use  of  poison  your  com¬ 
mittee  recommends  the  calcium  arsenate  dusting  method  and  the  01 1C  ^ 
Method.  There  are  no  other  methods  having  as  yet  the  sanction  of  a<  equa 
scientific  proof.  Whether  the  Florida  Method  will  succeed  elsewhere  (than 

Florida)  cannot  be  determined  until  further  studies  .  aie  ma.  e. 

“As  resnonsible  agencies  .  the  agricultural  colleges  can  recommend  to 

the  people  only  such  methods  as  have  been  fully  established  by  adequate  and 

dependable  scientific  data.” 

The  report  recommended  test  work  by  State  and  Federal  agencies  of 
other  methods. 


4 


1ST.  C.  Agricultural  Extension  Service 


The  dust-poison  method  kills  boll  weevils  and  thus  protects  the 
squares  and  bolls,  but  it  does  not  “make”  cotton;  hence  it  does  not  take 
the  place  of  the  Cultural  Methods  (advocated  from  the  Division  of 
Agronomy)  for  securing  an  early  setting  of  the  largest  possible  crop. 
Rather  the  dust-poison  method  should  supplement  (to  be  added  to)  the 
Cultural  Methods,  the  two  together  offering  the  best  chance  that  we 
now  know  to  grow  a  profitable  crop  of  cotton  under  heavy  weevil  infes¬ 
tation.  Also  let  us  make  it  clear  that  in  sections  (or  in  fields,  or  in 
years)  where  there  are  few  weevils  and  light  injury,  the  dust-method 
will  not  give  its  highest  returns,  and  that  it  does  give  its  highest  returns 
where  (or  when)  the  weevil  infestation  is  heaviest. 

The  dust-poison  method  appears  sound,  both  in  its  principles  and  its 
results.  It  has  proven  good  in  numerous  comparative  tests  by  the 
United  States  Bureau  of  Entomology  since  1916;  by  the  experience  of 
experimenters  in  the  several  states  south  of  us;  by  commercial  firms; 
and  by  our  own  experience  of  1922. 

Despite  objections  to  cost  of  machines  and  to  the  night  work,  the 
dust-method  stands  in  our  own  experience  as  a  profitable  method  for 
direct  control  of  boll  weevil,  and  it  renders  all  the  greater  opportunity 
of  a  more  certain  profit  when  the  Cultural  Methods  are  fully  employed. 
It  has  been  winning  its  way  by  definite  and  indisputably  profitable 
results. 

It  will  pay  the  farmer  to  study  the  method  as  described  in  this 
circular,  so  that  he  shall  know  what  to  do,  when  to  do  it,  and  how  to  do 
it.  It  is  also  important  that  he  should  not  go  astray  in  making  wasteful 
and  needless  applications  of  poison  in  fields  where  they  are  not  needed, 
or  at  times  when  they  are  not  profitable. 

The  dust  method  is  recommended  more  especially  for  fairly  fertile 
lands;  it  is  not  advised  to  dust  a  crop  which  is  naturally  capable  of  less 
than  about  one-third  or  one-half  bale  per  acre;  there  should  be  the 
reasonable  assurance  of  a  crop  worth  dusting. 

With  these  suggestions  plainly  given,  we  commend  the  dust-poison 
method  to  farmers  who  will  do  it  carefully. 

SUGGESTIONS  FOR  1923 

As  the  dust-poison  method  pays  best  under  heavy  weevil  infestation, 
we  do  not  advise  it  in  all  that  northern  part  of  the  North  Carolina 
cotton  area  where  injury  is  due  to  be  light  in  1923. 

The  region  where  we  do  advise  it  for  1923  is  south  of  a  line  drawn 
from  Hickory  in  Catawba  County  to  Salisbury  in  Rowan,  to  (10  miles 
south  of)  Raleigh  in  Wake,  to  (about  8  miles  north  of)  Washington  in 
Beaufort.  All  the  region  south  of  such  a  line  is  due  for  severe  injury  in 
1923;  and  in  the  southern  and  eastern  part  of  this  region  especially 
there  is  every  reason  to  expect  that  proper  dusting  will  pay  well.  In 
all  this  region  the  Cultural  Methods  for  early  setting  of  crop  should  be 
studiously  followed. 


Dust-Poison  Method  for  Control  of  Boll  Weevil  5 

In  the  region  north  of  the  line  indicated  the  injury  will  probably  he 
heavier  to  southward  and  eastward,  hence  in  such  sections  as  Edge¬ 
combe,  northern  Pitt,  Martin  and  eastward  there  will  likely  he  some 
fields  in  which  it  would  be  profitable.  A  year  hence  (season  of  1924) 
our  entire  cotton  section  up  to  the  Virginia  state  line,  will  be  due  for 
heavy  injury,  closely  approaching  the  full  normal  for  future  years.  In 
the  region  north  of  the  line  the  Cultural  Methods  for  early  setting  of 
crop  should  he  studiously  followed  as  a  preparation  for  the  future,  and 
we  advise  gathering  and  burning  the  squares  (if  practicable)  once  a 
week  to  middle  or  end  of  July. 

Order  Poison  and  Machines  Early. — There  is  likely  to  be  a  shortage 
of  calcium  arsenate  during  1923,  so  it  is  highly  important  that  those 
who  intend  to  dust  should  place  orders  early  for  their  poison,  and  the 
same  advice  applies  (perhaps  with  less  urgency)  to  machines.  Both 
poisons  and  machines  should  he  on  the  farms  before  June  1st,  even  though 
actual  dusting  might  not  begin  until  the  latter  part  of  July.  Calcium 
arsenate  should  he  bought  at  rate  of  25  to  30  pounds  for  each  acre  which 
it  is  intended  to  dust.  Likewise,  machines  should  he  ordered  according 
to  acreage,  making  sure  not  to  attempt  to  dust  too  large  an  acreage  for 
the  machines  you  have.  We  wish  to  emphasize  that  care  be  used  to 
follow  the  suggestions  and  directions. 

A  number  of  merchants  in  this  state  are  handling  approved  machines 
and  calcium  arsenate.  Consult  county  agent,  or  write  for  information. 

OPERATIONS  IN  1922 

Farmers  are  entitled  to  know  the  reasons  for  our  confidence  in  the 
proper  following  of  the  dust-poison  method. 

In  1922  we  undertook  to  advise  and  guide  those  who  would  use  the 
dust-poison  method  in  our  southern  counties  where  injury  was  due  to 
he  severe.  Upward  of  50  farmers  did  some  dusting.  We  were  in  com¬ 
munication  with  most  of  them  and  visited  many  of  the  fields.  About 
fifty  tons  of  calcium  arsenate  was  used.  At  close  of  the  1922  season  we 
gave  all  the  opportunity  to  describe  their  results,  experiences  and 
opinions.  The  replies  of  those  who  both  dusted  and  reported  are  quoted 
later — no  unfavorable  ones  withheld — we  give  the  entire  showing.  Some 

did  not  report. 

Mr  Mabee  was  located  in  Scotland  County  for  most  of  the  growing 
season,  and  personally  followed  the  work  on  five  farms  to  the  point  of 
securing  the  comparative  yield  of  dusted  and  undusted  cotton  (along¬ 
side  on.  uniform  land  in  same  field)  culture,  fertilization,  etc.,  being 
the  same.  In  Bladen,  county  agent  K.  K.  Craven  at  Clarkton  made  a 
similar  test  on  cotton  of  his  own  and  has  furnished  us  the  figures,  in 
Onslow,  county  agent  D.  L.  Latham  has  given  us  similar  figures  from 
the  work  of  Dr.  L.  D.  Bryan  at  Snead’s  Ferry.  These  seven  cases  we 
present  as  fair  comparative  demonstration  tests  under  field  conditions. 


6 


C.  AGRICULTURAL  EXTENSION  SERVICE 


The  results  of  these  tests,  all  figured,  on  bases  of  one  acre  (though  the 
plots  averaged  larger  than  one  acre)  are  shown  in  the  following  table: 

DEMONSTRATION  TESTS,  BOLL  WEEVIL  CONTROL,  1922 


Long  Staple  Cotton 


Name  and  County 

Times 

Yield  Seed 
Cotton  per 
Acre,  Pounds 

Gain  per 
Acre  by 
Dusting 

Cost 

of 

Dust¬ 

ing 

Net 

Profit 

per 

Dusted 

Dusted 

Not 

Dusted 

Pounds 

Seed 

Cotton 

Value 

per 

Acre 

for 

Season 

Acre  by 
Dust¬ 
ing 

Z.  V.  Pate,  Scotland _ _  .  . .  . .  . 

6 

1,883 

1,481 

402 

$48.24 

$  7.00 

$  41.24 

Short  Staple  Cotton 


1.  J.  N.  Gibson,  Scotland  .  ..  -- 

4 

1,311 

1,054 

257 

24.93 

2.88 

22.05 

2.  W.  N.  McKenzie,  Scotland _  -  .. 

5 

1,612 

1,464 

•  148 

14.22 

4.75 

9.47 

3.  McL.  Gibson,  Scotland _  __  _ 

5 

1,845 

1,468 

377 

36.53 

4.13 

32.40 

4.  J.  C.  Hunsucker,  Scotland..  ...  _ 

5.  R.  K.  Craven,  County  Agent,  Bladen 

3 

1,913 

1,705 

208 

20.02 

3.50 

16.52 

(own  work) _ 

6.  L.  D.  Bryan,  Onslow  (figures  by 

6 

1,000 

500 

500 

48.42 

10.92 

37.50 

County  Agent  Latham)...  .  _ 

6 

750 

410 

340 

32.78 

6.20 

26.58 

Average  for  six  short  staple  tests _ 

5 

1,405 

1,100 

305 

$29  .48 

$  5.40 

$  24.08 

Note. — The  figures  for  times  dusted,  yield  of  dusted  and  undusted  cotton, 
gain  by  dusting,  and  cost  of  dusting,  are  figured  from  the  records  of  the 
farmers  themselves  with  Mr.  Mabee  in  all  of  the  Scotland  County  tests — in 
the  other  two  cases  the  figures  are  from  county  agent. 

The  figures  on  value  of  gain,  and  net  profit  per  acre  by  dusting,  are  figured 
on  following  basis  at  suggestion  of  Mr.  Frank  Parker,  Agricultural  Statistician : 
Long  staple  cotton  at  32c.  per  lb.  for  lint ;  short  staple  at  25c.  per  lb.  for 
lint ;  also  that  one-tliird  of  weight  of  gain  was  lint,  and  two-tliirds  seed. 

We  have  figured  all  seed  at  2c.  per  pound,  which  we  believe  conservative. 

The  figures  for  cost  of  dusting  includes  labor  and  poison  on  1922  prices,  and 
also  includes  an  allowance  for  wear  on  machines  except  in  case  of  Mr.  Craven, 
who  in  making  liberal  allowance  for  poison  says  that  he  thinks  the  cost  as 
given  is  sufficient  without  further  allowance  for  machine,  which  he  says  is 
yet  in  good  condition. 

Comment. — The  highest  gain  in  pounds  of  seed  cotton  is  by  Mr.  Craven  in 
Bladen,  who  says  that  his  figures,  although  “round,”  are  very  close  to  exact 
accuracy ;  he  was  under  heavy  infestation  and  made  heavy  applications  on 
account  of  rains. 

The  lowest  gain  is  by  Mr.  McKenzie,  whose  undusted  plat  was  very  narrow, 
and  presumably  received  some  poison  while  dusting  adjoining  rows,  thus 
lessening  the  difference.  In  another  test  (separate  from  ours)  his  gain  was 
368  lbs.  seed  cotton  per  acre.  His  average  gain  for  the  two  tests  was  therefore 
258  lbs.  seed  cotton  per  acre. 

The  highest  net  profit  per  acre  by  dusting  is  by  Mr.  Pate,  whose  cotton  was 
Delta  Type  long  staple.  His  test  is  therefore  not  included  in  the  avei'age  at 
bottom  of  table,  which  is  for  six  short-staple  tests  only. 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


hr 

i 


TESTIMONY  OF  OTHER  FARMERS 

The  testimonials  which  follow  are  not  so  clearly  convincing  as  the 
results  given  in  the  preceding  table,  because  of  the  lack  of  definite  com¬ 
parative  figures.  The  season  of  1922  was  rainy,  and  we  include  letters 
to  show  how  some  were  ^discouraged  by  the  rains,  while  others  were 
making  profitable  gains  by  dusting  during  the  same  rainy  season. 

ANSON  COUNTY 

Mrs.  Bessie  Little,  Wadesboro: 

“One  white  tenant  dusted  about  7  acres  with  hand-duster,  two  acres 
separated  by  road  was  dusted  three  times ;  says  that  dusted  three  times  had 
top  cotton  while  the  other  did  not.  It  is  his  opinion  that  it  paid.” 


Mr.  W.  C.  Hall,  manager  for  Eli  Griggs,  Wadesboro : 

“We  think  we  got  some  results  from  dusting.  While  it  rained  continually 
during  the  dusting  period,  we  picked  21  bales  cotton  from  the  16  acres 
dusted.”  (This  was  in  spite  of  heavy  infestation  in  mid-July,  as  shown  in 
our  notes. — F.  S.) 


-  Mr.  Lester  Ratliff,  Morven: 

“Don’t  know  just  what  to  say  about  it,  as  we  had  so  much  rain  during 
the  time  we  were  trying  to  use  the  dust  we  didn’t  get  a  fair  test  of  it.  I 
think  we  must  have  gotten  some  good  from  it,  but  the  fields  we  dusted  had 
so  many  more  weevils  than  the  ones  we  didn’t  dust  that  it  would  be  hard 
to  tell.” 

Mr.  L.  G.  Atkinson,  Wadesboro  (place  25  miles  out  farmed  by  colored  tenant)  : 

“Had  about  16  acres  in  cotton  and  used  mule-back  duster  (Saddle-gun)  with 
very  good  results.  Could  not  leave  fair  undusted  plat  for  comparison,  but 
feel  quite  sure  the  operation  paid.  Dusted  four  or  five  times  after  and 
during  big  rains  in  first  of  August.  Expect  to  use  duster  coming  season  if 
weevils  show  up  as  they  did  this  year.  I  wish  to  thank,  (etc.) 


BLADEN  COUNTY 


R.  IC.  Graven,  County  Agent: 


( See  figures  from  his  own  cotton  in  table  on  page  6. ) 

“Mr.  James  Stevens,  Council,  N.  C.,  with  50  acres  Cleveland  cotton  esti¬ 
mated  that  he  made  400  lbs.  more  seed  cotton  per  acre  by  dusting,  five  appli¬ 
cations,  6  lbs.  per  acre  each  time.  His  brother  did  not  da  so  \\e  .as  i. 

planted  another  variety  cotton.” 


ONSLOW  COUNTY 


Mr.  (name  withheld),  Richlands : 

“I  did  not  dust  this  year.  It  was  too  rainy 


for  dusting  to  pay.” 


Mr. 


(name  withheld),  R.  D. 
“I  didn’t  do  any  dusting. 


1,  Jacksonville: 

It  is  useless  to  dust  when  it  rains  every  day 


See  figures  for  Dr.  L.  D.  Bryan, 
what  dusting  did  during  that  rainy 


Onslow 

season. 


County,  in 


table  on  page  6,  to  see 


8 


E.  C.  Agricultural  Extension  Service 


RICHMOND  COUNTY 

Mr.  TV.  H.  Barton,  County  Agent,  Rockingham: 

“A  marked  difference  can  be  seen  in  the  top  crop  of  fields  dusted  and  those 
not  dusted.  Those  who  dusted,  so  far  as  I  can  determine,  did  not  leave 
undusted  plats  for  comparison.” 

Mr.  L.  F.  Thomas,  Rockingham  : 

“Did  not  dust ;  only  a  few  weevils  in  spots  till  about  close  of  opening 
season.  Planted  about  6  acres  ordinary  land  and  made  4  bales  with  no 
dusting.  I  think  that  did  very  well.” 

Mr.  TV.  N.  Everett  (Everett  Farms),  Rockingham: 

“We  tried  some  of  the  various  methods  and  the  dusting  method  recom¬ 
mended  by  the  Department.  While  we  kept  no  accurate  account  of  cotton 
picked  from  acres  so  treated,  both  our  superintendent  and  the  writer  agree 
that  the  methods  advocated  by  your  department  gave  materially  better 
results  than  any  other  method  used.” 

SCOTLAND  COUNTY 

(See  figures  in  table  on  page  6  for  results  other  than  reported  here.) 

Mr.  H.  TV.  Malloy,  Laurinburg: 

“One  acre  not  dusted,  700  lbs.  seed  cotton ;  one  acre  dusted,  724  lbs.  seed 
cotton. 

“I  might  add  that  this  land  should  not  have  been  dusted,  as  its  normal 
production  is  only  about  900  lbs.  per  acre. 

“On  the  rest  of  the  crop  which  was  dusted  I  feel  confident  that  the  dust¬ 
ing  paid,  and  it  is  my  intention  to  dust  all  my  cotton  in  1923  on  land  which 
would  normally  produce  as  much  as  1,200  lbs.  seed  cotton  per  acre.  Sorry 
my  figures  are  not  more  favorable,  but  I  will  continue  to  dust.” 

(If  his  dusting  was  well  done,  the  small  gain  would  indicate  that  his  infesta¬ 
tion  was  light. — F.  S.) 

H.  TV.  McLaurin,  Johns: 

“I  used  the  dust  on  my  cotton  this  season,  and  am  sure  it  paid  well.  Am 
satisfied  it  increased  my  crop  15  per  cent.” 

Mr.  D.  K.  McRae,  Laurinburg : 

“I  made  enough  on  a  few  acres  to  pay  for  the  machine  and  the  arsenate. 
On  a  field  of  7  acres  we  made  7  bales,  by  four  dustings.  On  10  acres  of  long 
staple  cotton  we  made  8  bales. 

“Where  we  did  not  dust  we  made  about  y2  bale  per  acre.  It  rained  so 
continuously,”  ( etc. ) . 

Mr.  E.  S.  Gibson,  Johns: 

“Used  dust  on  13  acres.  This  made  12  bales.  Another  crop  (not  dusted) 
of  12  acres  made  8  bales ;  another  of  22  acres  made  14  bales ;  but  this 
difference  was  not  altogether  due  to  dusting,  for  the  land  where  dusting 
was  done  would  make  more  than  the  other  anyway.” 

Mr.  G.  G.  Mathews,  Laurel  Hill: 

“Made  two  applications  of  dust,  and  while  I  did  not  weigh  in  on  the  check 
plat,  I  am  satisfied  that  it  paid  me.  Arranging  to  dust  our  entire  acreage 
next  year,  and  we  have  it  understood  with  our  tenants  that  they  are  to 
apply  this  poison.  Thanking,  .  .  .  complimenting,”  (etc.). 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


9 


UNION  COUNTY 

Mr.  (name  withheld),  R.  D.  1.  Monroe: 

“I  did  not  dust.  The  boll  weevil  got  my  cotton.  Made  only  4  bales  on  10 
acres,  where  I  usually  make  10  bales.” 

Mr.  H.  G.  Boyce,  R.  D.  5,  Monroe : 

“I  dusted  a  good  deal  and  am  well  pleased  with  results,  but  did  not  have 
any  check  (undusted)  plats.  On  1 %  acres  dusted  three  times  I  got  a  bale 
of  475  lbs.  lint.  Dusted  as  late  as  August  20.  Expect  to  dust  on  larger 
scale  in  1923.  Wish  to  thank,”  (etc.). 

COMMENT  ON  TESTIMONY  OF  FARMERS 

It  will  be  noticed  that  while  some  report  that  they  could  not  dust  on 
account  of  rains,  yet  in  the  same  counties  others  who  'persisted  made  good 
results  by  dusting.  Also,  the  results  in  our  table  of  comparative  tests 
on  page  6  show  a  substantial  profit  per  acre  in  every  case.  It  would 
seem  that  the  season  would  have  to  be  more  rainy  than  1922  to  justify 
a  neglect  of  dusting.  Indeed  the  general  experience  elsewhere  has  been 
that  dusting  is  most  needed,  and  often  gives  its  highest  profits  in  seasons 
which  are  classed  as  “rainy.” 

CHIEF  DIFFICULTIES 

It  is  fair  that  we  should  frankly  recognize  the  chief  difficulties  which 
we  encountered. 

Rains. — Bains  were  frequent  in  season  of  1922,  yet  the  dusting  paid 
well.  The  treatments  gave  enough  profit  so  that  if  one  had  to  give  two 
(or  even  three)  dustings  in  succession  to  get  one  that  was  fully  effective, 
there  might  still  be  a  good  profit. 

Hence  we  suggest  to  take  a  chance  on  the  weather  and  dust  even  in 
the  prospect  of  a  rain  rather  than  neglect  it  after  the  dusting  point  is 
reached.  In  this  matter  the  grower  has  the  chance  to  show  judgment 
and  skill,  and  can  profit  by  being  prepared  to  take  advantage  of  every 
chance.  The  official  weather  forecasts  may  help.  While  rains  did 
interfere,  all  our  tests  were  profitable  in  spite  of  them.  We  aimed  to 
dust  as  the  directions  say  (“How  to  Poison,”  pages  20-21),  and  if  a  rain 
threw  us  out  of  the  schedule  we  returned  to  it  at  the  earliest  opportunity. 

The  Night  Worlc. — We  did  not  find  this  impossible  or  impracticable. 
Many  farmers  (tobacco-growers  especially)  do  night  work  at  certain 
seasons.  Small  areas  of  cotton  may  be  dusted  in  part  of  a  night.  Very 
large  areas  may  call  for  all-night  work  for  some  men  or  shifts  of  pai  t- 
night  each. 

It  is  well  to  arrange  in  advance  to  have  a  thoroughly  competent  work¬ 
man  do  this  work  at  the  start  (or  do  it  one’s  self)  and  break  in  others 
as  they  learn  by  observation  and  by  helping.  Have  at  least  one  extra 

lantern. 

In  the  hot  weather  of  July  and  August  night  work  is  cooler  than  day 
work. 


10 


AT.  C.  Agricultural  Extension  Service 


Breakage  and  Wear  of  Machines. — With  the  horse-machines  trouble 
on  this  score  was  severe  in  hilly  and  stony  fields,  where  broken  links  or 
cogs,  wearing  of  gears,  etc.,  were  more  or  less  frequent.  We  know  of 
two  in  Anson  County  whose  experience  was  flatly  discouraging  on  this 
account.  In  such  fields  we  believe  the  tendency  will  be  toward  the 
Hand-guns  and  Saddle-guns. 

A  certain  amount  of  mechanical  ingenuity  is  helpful  in  setting  up  a 
machine  in  first  place  and  in  keeping  it  in  working  order  afterward. 
The  printed  directions  with  a  new  machine  should  be  noticed.  Extra 
parts  most  subject  to  wear  should  be  quickly  available.  The  grower 
and  operator  should  become  familiar  with  the  machine,  test  it  out  and 
watch  its  workings,  before  the  time  for  actual  dusting  arrives.  There 
are  plenty  of  farm  machines  (not  to  mention  autos)  which  are  more 
complex  and  difficult  than  the  cotton-dusting  machines. 

Regulating  Amount  of  Poison  Per  Acre — Clogging  of  Pipes,  Etc. — 
The  general  directions  are  to  use  “5  to  7  pounds  per  acre  for  each  appli¬ 
cation. ”  While  the  machines  have  a  device  for  regulating  the  flow  of 
dust,  yet  these  are  not  always  accurate,  and  it  is  advisable  to  make  a 
test  on  a  few  acres  and  correct  it  if  needed.  Farmers  have  the  tendency 
to  use  more  poison  than  necessary;  this  may  be  on  the  side  of  safety, 
but  it  may  easily  run  into  needless  expense. 

A  pipe  may  clog  so  that  its  flow  of  dust  is  not  adequate ;  a  kink,  a  bit 
of  trash  in  feeding  device,  or  a  “caking”  of  the  dust  by  moisture  at  some 
point.  Experience  soon  helps  to  prevent  or  remedy  these  difficulties. 
Sheer  accidents,  such  as  running  a  machine  into  a  stump  or  ditch,  may 
be  costly.  While  the  operation  is  yet  new,  it  is  best  to  entrust  it  only  to 
reliable  workmen. 

When  to  Begin  to  Dust. — The  directions  say :  “Start  poisoning  when 
the  weevils  have  punctured  from  10  to  15  per  cent  of  the  squares.” 
That  time  of  10  per  cent  puncturing  (or  more)  we  therefore  call  the 
“dusting  point,”  and  our  experience  indicates  that  it  is  abundantly  worth 
while  for  the  farmer  to  know  how  to  determine  when  this  point  is 
reached.  And  it  is  quite  simple ;  here  it  is : 

Examine  100  squares  in  each  of  3  to  6  typical  spots  in  the  field  (300  to  600 
squares  in  all).  These  spots  should  be  well  separated  and  representative  of 
the  field  in  general.  Open  the  shuck  and  examine  the  bud,  doing  this  with 
squares  low  on  plants  as  well  as  in  top,  examining  those  large  enough  to  be 
attractive  to  weevil  (experience  will  soon  teach).  Do  not  pick  unpunctured 
squares,  but  ones  showing  the  usual  pimple-like  “puncture”  should  be  picked 
and  put  in  pocket.  Having  thus  examined  100  squares  on  one  or  two  rows  at 
the  first  spot,  you  now  count  the  punctured  squares  in  pocket.  If  there  are 
15,  write  down  on  your  piece  of  paper  “15”  for  the  first  spot.  Go  to  the  next 
spot  and  make  similar  count  and  examination ;  perhaps  here  you  will  find  “27,” 
and  write  it  down.  The  third  spot  may  show  “9,”  and  the  fourth  may  give 
“11.”  You  then  merely  average  the  four  counts:  15+27+9+11=62  (divide 
by  4  to  get  average)  =15%  per  cent  for  the  four  spots,  and  as  this  is  over  10 
per  cent,  dusting  should  at  once  begin. 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


11 


It  is  entirely  simple,  and  any  person  who  has  the  least  aptitude  for 
figuring  can  become  proficient  in  an  hour  of  actually  doing  it.  Four  to 
six  spots  in  a  field  of  5  to  10  acres  can  be  adequately  examined,  and 
calculation  made,  in  one-half  to  one  hour  by  one  person.  If  a  certain 
side  or  end  of  field  is  found  to  be  regularly  much  more  heavily  infested 
earlier  in  season  than  the  rest  of  the  field,  that  portion  may  be  given  an 
earlier  dusting.  If  the  infestation  seems  reasonably  uniform  (or  with 
many  bad  spots)  over  the  whole  field,  then  dust  the  whole  when  the 
general  average  reaches  10  per  cent.  But  the  examination  should  be 
fair ,  including  squares  low  on  plants  as  well  as  high,  as  otherwise  one 
may  merely  deceive  one’s  self. 

There  is  much  sentiment  for  poisoning  the  first  weevils,  killing  them 
before  the  10  per  cent  point  is  reached,  etc.  Our  experience  indicates 
that  this  may  be  misleading  and  is  apt  to  result  in  waste.  To  wait  until 
10  per  cent  of  the  squares  are  punctured  does  not  mean  that  10  per  cent 
of  the  crop  is  destroyed,  for  there  is  normally  a  surplus  of  squares.  In 
1922  there  were  many  fields  in  our  southern  counties  which  had  weevils 
•from  the  time  they  came  out  of  winter-hiding  (late  May),  yet  which 
did  not  reach  the  “dusting  point”  (of  10  per  cent  of  squares  being 
punctured)  until  a  good  crop  was  well  assured;  such  fields,  not  dusted 
at  all,  often  yielded  as  much  as  in  former  years;  to  have  dusted  them 
early  apparently  would  have  been  wasteful.  But  there  were  other  fields 
in  which  the  “dusting  point”  (of  10  per  cent)  was  reached  by  middle  or 
end  of  July;  in  such  fields  those  that  were  well  dusted  made  a  full  (or 
nearly)  normal  crop,  and  those  which  were  not  dusted  made  much  less 
than  a  normal  crop.  Our  experience,  with  many  examinations  and 
counts  recorded  in  our  notes,  indicated  over  and  over  again  that  hun¬ 
dreds  of  dollars  could  easily  be  wasted  by  needless  dusting,  and  hun¬ 
dreds  of  dollars  gained  by  dusting  when  it  was  needed. 

In  1922  in  our  southern  counties  the  “dusting  point”  (of  10  per  cent) 
was  reached  in  heavily  infested  fields  from  July  12  to  August  1,  and 
averaged  about  July  25,  approximately  two  months  after  wee\  ils  fiist 
appeared  in  the  fields.  For  two  months,  with  weevils  m  the  fields,  v  e 
sat  tight  and  saved,  as  one  farmer  figuratively  remarked:  “waiting  until 
we  could  see  the  whites  of  the  enemies’  eyes  before  firing.”  Then,  when 
the  “dusting  point”  (of  10  per  cent)  was  reached,  in  late  July,  we  began 
the  dusting,  and  our  results  were  profitable  in  every  case ,  as  shown  m 

table  on  page  6. 

If  the  dusting  practice  becomes  permanently  common  among  our 
people,  undoubtedly  this  point  of  when  to  begin  dusting  will  become 
more  or  less  fixed  by  community  practice,  the  more  careful  farmers 
setting  the  pace,  and  the  time  to  begin  may  vary  from  year  to  year 
according  to  severity  of  infestation.  Our  effort  m  1922  was  and  oiu 
effort  in  writing  these  pages  is,  to  point  the  way  safely  for  the  moie 


12 


N.  C.  Agricultural  Extension  Service 


careful  farmers.  Dusting  need  not  begin  on  any  fixed  date;  it  depends 
on  the  weevil  infestation,  not  on  the  calendar.  Gradually  approximate 
calendar  dates  may  come  into  use. 

We  readily  grant  that  as  the  “dusting  point”  approaches,  it  is  better 
to  begin  dusting  a  little  before  it  is  actually  reached  than  to  delay  too 
long. 

MACHINERY  FOR  COTTON  DUSTING 

There  are  four  general  types  of  cotton  dusting  machines,  adapted  to 
different  acreages  or  conditions.  Between  makes  of  machines  of  the 
same  type  there  is  room  for  difference  of  opinion.  A  number  of  mer¬ 
chants  in  the  State  are  handling  machines.  Consult  county  agents  or 
farmers  who  have  had  good  experience,  or  write  us  for  information. 


Fig.  1. — Hand  gun  in  operation  in  cotton  field. —  ( From  U.  S.  Dept.  Agr.) 


Hand-gun. — Carried  by  operator,  worked  by  hand,  treats  one  row  at 
time.  One  machine  can  take  care  of  5  to  8  acres  of  cotton  for  the 
season.  Better  not  attempt  these  on  more  than  20  to  25  acres.  Lasts 
one  to  three  years  according  to  care  and  use.  Costs  from  $12  to  $20. 
(See  Eig.  1.) 

The  Hand-guns  are  in  favor  for  small  acreages,  odd  patches,  short 
rows,  etc.,  for  those  of  limited  means,  or  for  getting  preliminary  ex¬ 
perience  first  season.  One  or  more  may  well  be  used  on  larger  plantings 
to  supplement  the  larger  machines. 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


13 


Fig.  2. — Saddle  gun  in  operation  in  cotton  field. —  ( From  U.  S.  Dept.  Ayr.) 


14 


AT.  C.  Agricultural  Extension  Service 


Saddle-gun. — This  is  a  type  of  duster  which  is  carried  on  mule-hack 
and  operated  by  rider,  treating  two  rows  at  time  (one  each  side).  One 
machine  can  take  care  of  about  50  acres  of  cotton  for  the  season,  and 
should  last  1  to  3  years.  Costs  around  $50  or  more  according  to  attach¬ 
ments.  This  type  is  quite  in  favor  for  rough,  stumpy,  irregular  land, 
with  short  rows,  etc.  (See  Eig.  2.) 

The  Saddle-guns  seem  to  be  winning  their  way  rapidly,  especially 
for  rough,  hilly,  or  wet  lands,  irregular  rows,  etc. 

One-mule  Machine. — Operated  by  one  man  and  one  mule;  runs  be¬ 
tween  rows  like  walking-cultivator  on  single  wheel,  which  is  geared  to 
fan.  Treats  two  rows  at  time  (one  each  side).  One  machine  can  take 
care  of  50  to  60  acres  of  cotton  for  the  season,  and  should  last  3  to  5 
years.  Costs  around  $100  to  $125.  (See  Eig.  3.) 

There  are  many  who  favor  the  One-mule  Machines  because  of  their 
adaptability  for  rapid  work,  the  fan  being  driven  by  the  wheel  instead 
of  by  hand.  We  expect  them  to  gain  in  favor  more  especially  in  the 
smoother,  more  level  lands  of  our  eastern  counties. 

Cart  Machine. — Two-wheeled  machine,  straddles  one  row,  operated 
by  one  man  (who  rides)  and  drawn  by  two  mules.  Treats  3  rows  at 
time.  One  machine  can  take  care  of  about  100  acres  of  cotton  for  the 
season,  and  should  last  4  to  6  years.  Wheels  geared  to  fan.  Costs 
around  $250  or  more.  (See  Eig.  4.) 

As  yet  but  few  of  these  larger  machines  have  been  used  in  this  State. 
ATaturally  they  are  for  larger  acreages,  and  better  suited  to  level  fields, 
as  in  our  eastern  counties.  From  what  we  hear  they  have  given  satis¬ 
faction. 

Equipping  with  Dusting  Machines. — We  do  not  care  to  here  express 
any  preference  for  particular  machines — your  own  opinion  after  expe¬ 
rience  might  be  different  from  ours — but  we  may  help  you  to  decide  on 
the  type  of  machines  to  use.  Let  us  “suppose”  several  classes  of  farmers : 

(1)  Growing  5  acres  cotton  on  one  farm. — One  Hand-gun  should  be 

enough  for  a  case  of  this  kind. 

(2)  Growing  10  acres  cotton  on  one  farm. — Two  Hand-guns,  which  would 

be  cheaper,  or  one  Saddle-gun,  which  could  handle  the  work  more 
rapidly  and  with  greater  certainty. 

(3)  Growing  20  acres  cotton,  one  farm. — Four,  or  better  five,  Hand¬ 

guns  might  do,  but  it  would  be  better  to  have  one  Saddle-gun,  or 
one  One-mule  Machine.  Might  be  well  to  have  one  Hand-gun 
(extra)  for  short  rows,  odd  corners,  etc. 

(4)  Growing  50  acres  cotton,  one  farm. — Either,  one  Saddle-gun,  or 

preferably  one  One-mule  Machine.  We  would  advise  one  Hand-gun 
in  addition. 

(5)  Growing  75  acres  cotton,  one  farm. — Two  Saddle-guns,  or  two  One- 

mule  Machines  (one  might  do),  or  one  of  each  type.  A  Hand-gun 
also  would  be  handy. 

(6)  Growing  about  100  acres,  one  farm. — Either  one  Cart-machine,  or 

two  Saddle-guns  or  two  One-mule  Machines,  or  one  Saddle-gun 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


15 


16 


1ST.  C.  Agricultural  Extension  Service 


and  one  One-mule  Machine,  with  also  a  Hand-gun  for  odd  places, 
etc.  We  would  incline  toward  two  less  expensive  machines  rather 
than  one  more  expensive  one — your  preference  may  lead  to  the 
other  decision. 

(7)  Cotton  on  several  farms. — For  a  case  of  this  kind  we  believe  it  better 
to  equip  for  each,  separately — for  there  is  delay  and  wear  in  haul¬ 
ing  a  machine  from  farm  to  farm — one  might  get  good  benefit  and 
the  other  not,  or  even  both  might  fail  of  proper  benefit.  If  several 
farms  with  small  acreage  each  are  close  together,  one  of  the  larger 
capacity  machines  may  do  for  several — but  be  careful. 

We  incline  to  advise  one  to  go  conservatively  in  his  first  attempts  at 
dusting,  furnishing  ample  machinery  for  the  one  or  more  fields  which 
are  to  be  dusted,  even  if  other  fields  are  left  undusted  in  the  first  year’s 
experience.  Certainly  it  is  not  safe  to  go  beyond  the  capacity  of  a 
machine — thus  we  have  given  the  capacity  of  the  One-mule  type  as  50 
to  60  acres  for  season;  if  one  were  to  attempt  to  dust  75  to  100  acres 
with  one  One-mule  Machine,  he  almost  certainly  could  not  get  over  the 
whole  at  the  frequent  intervals  (4  days,  preferably)  that  is  desirable  at 
the  height  of  the  dusting  season,  and  would  perhaps  fail  of  proper  result 
on  the  whole  100  acres;  whereas,  if  he  limited  it  to  its  proper  capacity 
of  50  to  60  acres,  his  result  might  be  highly  profitable. 

We  have  mentioned  Hand-guns  to  supplement  the  larger  machines  for 
larger  acreages.  They  are  handy  for  corners,  odd  rows,  stumpy  places, 
or  in  an  emergency  when  the  larger  machine  might  be  out  of  order.  But 
the  hand-operated  machines  are  more  tiring  on  the  operator  and  less 
regular  in  their  delivery  of  dust  (when  operator  is  tired)  than  the 
wheel-geared  machines.  The  wheel-geared  machines  are  less  expensive 
in  operation  (especially  on  the  item  of  labor  cost),  though  they  are 
more  expensive  in  purchase-price;  and  in  our  experience  broken  links, 
etc.,  are  often  frequent. 

While  we  cannot  discuss  every  condition  of  farms  and  acreage,  we 
have  tried  to  go  far  enough  into  this  detail  to  show  that  one  should  con¬ 
sider  carefully  how  much  acreage  he  will  attempt  to  dust,  should  order 
ample  machinery  for  that  acreage,  and  then  not  attempt  greater  acreage 
than  the  machinery  can  handle. 

And  a  good  general  guiding  rule  is:  have  enough  machinery  to  get 
over  the  acreage  in  three  full  night's  work.  This  is  the  general  basis  on 
which  we  have  stated  the  acreage  capacity  of  the  machines:  thus,  by 
indicating  the  capacity  of  One-mule  Machine  at  50  to  60  acres,  we  mean 
that  the  machine  should  dust  that  acreage  in  3  full  nights  operations 
(i.  e.,  from  14  to  20  acres  per  night).  Allowing  one  night  for  rain  or 
delays,  this  gets  over  the  entire  acreage  at  four-day  intervals. 

Of  course  the  acreage  covered  will  depend  on  the  skill  and  industry 
of  operator,  and  the  rate-of-step  of  mule,  etc.  And  the  number  of  years 
that  a  machine  will  last  will  depend  on  care  and  use. 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


17 


Fig.  4. — Cart  machine  in  operation  in  cotton  field;  with  acetylene  light.  From  U.  S.  Dept.  Agr.) 


18 


JNT.  C.  Agricultural  Extension  Service 


CALCIUM  ARSENATE  (The  Poison) 

As  this  is  written,  there  is  prospect  of  a  shortage  of  this  in  1923,  and 
we  hope  that  it  will  be  relieved  before  1924.  Under  a  similar  but  less 
acute  shortage  in  1922  our  growers  who  ordered  early  (March  to  May) 
secured  what  they  ordered.  This  year  (1923)  we  are  urging  early  order¬ 
ing,  and  we  are  informed  of  many  tons  (even  carloads)  already  in  the 
State.  Whether  one  wishes  to  order  independently  or  in  cooperation 
with  others,  our  advice  is  to  place  the  order  without  delay.  A  number  of 
merchants  in  the  State  are  handling  this  material.  Consult  county 
agent,  or  write  for  information.  Present  prices  range  from  17  to  21 
cents  per  pound,  according  to  quantity,  etc. 

How  Much  to  Order. — We  advise  ordering  25  to  30  pounds  of  calcium 
arsenate  for  each  acre  it  is  intended  to  dust — the  smaller  amount  will 
cost  less,  but  the  larger  amount  is  safer  as  allowing  for  some  waste  by 
rains,  etc.  Thirty  pounds  would  permit  of  five  dustings  of  6  lbs.  per 
acre  each.  Experience  indicates  that  generally  the  number  of  dustings 
needed  varies  from  3  to  6 — with  occasional  cases  where  more  than  six 
may  be  needed,  or  where  less  than  three  may  do.  If  one  has  poison  left 
over  it  may  be  sold,  or  it  is  good  for  another  year  if  kept  perfectly  dry. 
The  man  who  must  economize  to  the  limit  and  who  may  lack  confidence 
in  the  method,  may  order  a  minimum — hut  he  who  is  proceeding  with 
safe  and  studious  confidence  will  see  the  wisdom  of  having  plenty  for 
his  needs  and  then  using  it  at  the  time  when  it  gives  best  profit,  at 
proper  rate,  at  proper  intervals. 

“HOW  MANY  ACRES  SHALL  I  DUST?’’ 

This  must  depend  on  your  ability  and  willingness  to  provide  adequate 
machines  and  poison — and  the  ability  of  your  labor  organization  to 
handle  the  work.  Those  with  small  acreage  and  fair  means  may  under¬ 
take  to  dust  all  their  cotton.  Those  with  large  acreage,  scattered  farms, 
indifferent  labor,  or  limited  means,  may  well  prepare  to  have  only  one, 
or  a  few,  of  their  fields  dusted,  these  to  be  selected  among  those  workers 
who  are  most  competent,  or  whose  fields  are  most  infested — and  expand 
their  operations  in  years  to  follow  as  experience  points  the  way. 

While  yet  lacking  in  actual  experience,  one  may  well  give  much 
thought  to  having  his  first  dusting  properly  done  (“Do  It  Right  or  Hot 
at  All”),  for  all  the  great  body  of  experience — not  only  our  own,  but  in 
other  states  also — indicates  that  success  lies  in  having  such  a  plan  ade¬ 
quately  provided  for. 

IMPORTANT  POINTS  TO  OBSERVE — OR  AVOID 

1.  Dusting  Protects,  but  does  not  “make”  a  Crop. — Do  not  imagine  that 
mere  “dusting”  will  make  a  profitable  crop  of  cotton  in  spite  of  boll 
weevil — it  will  not.  The  very  best  of  Cultural  Methods  for  securing 
the  largest  possible  “setting”  of  the  earliest  possible  crop  are  highly 
important.  In  the  fields  where  our  comparative  tests  were  conducted 


19 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


in  1922  (see  table,  p.  6)  the  Cultural  Methods  were  generally  «-00d, 
so  that  even  the  undusted  cotton  gave  fair  yields;  and  then  when 
we  applied  the  dust-poison  method,  substantial  additional  profits  were 
secured  by  the  dusting.  A  late,  poor,  stunted  crop  on  thin,  poor 
land,  carelessly  cultivated,  might  be  a  losing  proposition  anyway,  and 
dusting  (even  if  well  done)  on  such  a  crop  might  not  pay.  There 
should  be  the  reasonable  assurance  of  a  crop  worth  dusting.  It  is 
not  advised  to  dust  a  crop  naturally  capable  of  less  than  about  one- 
third  or  one-half  bale  per  acre.  And  of  course,  by  good  cultural 
methods  many  profitable  crops  are  raised  without  dusting. 

2.  Study  Pays. — We  know  of  no  substitute  for  intelligent  care  and  proper 
study  in  meeting  the  boll  weevil  problem.  As  in  any  other  test,  some 
have  failed  in  this  test,  and  others  have  “kept  on  their  feet.’’ 

Follow  Directions. — Give  careful  heed  to  the  brief  explicit  directions 
under  “How  to  Poison,’’  on  pages  20-21.  These  directions  are  simple, 
clear  and  definite;  in  our  experience  thus  far  success  lies  in  following 
them. 


3 


4.  Precaution  Against  Possible  Danger. — Although  about  50  tons  of  poison 

was  dusted  on  cotton  in  North  Carolina  in  1922,  we  have  not  heard 
of  any  case  of  death  or  sickness  (even  of  farm  animals)  which  was 
laid  to  this  dust-poison  method. 

Yet  it  should  be  remembered  that  calcium  arsenate  (an  innocent- 
looking  white  powder)  is  poisonous.  The  containers  should  be  kept 
closed,  so  the  material  will  not  be  reached  by  children  or  animals. 
In  using  the  horse-drawn  machines  put  a  muzzle  on  animal,  especially 
if  inclined  to  nil)  at  plants;  however,  in  all  except  the  hand-guns,  the 
poison  is  delivered  behind  or  below  both  animal  and  operator  so  the 
animal  is  usually  between  unpoisoned  rows.  The  operator  should 
breathe  as  little  of  the  dust  as  possible.  After  dusting  work  the 
horse  may  be  cleaned  or  curried;  and  operator  should  wash,  clean 
finger  nails,  brush  off  clothes  and  (if  possible)  change  garments. 
With  these  cautions  we  have  heard  of  no  accidents. 

With  the  several  weeks  that  elapse  after  last  dusting  and  before 
picking,  the  poison  disappears  to  such  extent  that  after  picking  the 
cotton  may  be  grazed. 

5.  Don’t  be  too  Uneasy  About  the  Early  Weevils. — An  anxious  grower 

may  easily  w-aste  time,  poison,  and  wear  of  machines  in  wasteful  dust¬ 
ings  for  early  weevils.  It  is  advised  to  “start  poisoning  when  weevils 
have  punctured  10  to  15  per  cent  of  the  squares.’’  Our  experience 
was  that  this  time  arrived  (approximately)  after  middle  of  July. 
This  threw  the  main  dusting  operation  into  a  short  season  (4  to  6 
weeks)  when  the  crop  needed  the  protection  most. 

In  case  weevils  seem  to  be  so  abundant  before  squares  begin  to 
form  as  to  puncture  a  destructive  percentage  as  fast  as  the  squares 
are  well  formed,  it  would  then  be  advisable  to  make  the  first  applica¬ 
tion  when  the  cotton  starts  squaring  freely,  or  about  the  time  the 
plants  average  from  4  to  5  squares  each.  While  this  necessity  appa¬ 
rently  arose  under  the  heavy  spring  emergence  of  1922  in  some  of 
the  states  south  of  us,  we  did  not  observe  it  in  North  Carolina  in  the 

same  year. 

The  “Florida  Method”  includes  a  distinct  and  separate  procedure 
aimed  at  the  early  weevils — but  its  adaptation  to  this  State  is  not  yet 

worked  out. 


20 


N.  C.  Agricultural  Extension  Service 


There  was  a  period  of  two  weeks  or  more  (late  June  to  early  July,, 
1922)  when  weevils  were  scarce — this  was  a  natural  interval  between 
the  over-wintered  generation  which  had  died  off  and  the  newly  bred 
next  generation.  This  deceived  many  who  thought  they  already  had 
the  weevil  under  control.  The  same  natural  interval  occurred  where 
no  effort  was  made  against  the  early  weevils. 

Our  profitable  result  in  every  case,  by  waiting  until  the  10  per 
cent  point  was  reached,  justifies  us  in  advising  not  to  break  hastily 
away  from  the  definite  directions.  Better  to  cling  to  what  has  proven 
good  until  clear  tests  or  contrary  experience  shall  point  the  way  to 
still  more  profitable  proceedings. 

6.  How  Arrange  Nozzles  for  Delivery  of  Poison?  The  Hand  Guns  de¬ 
liver  the  dust  obliquely  downward,  and  with  them  we  prefer  to  hold 
the  nozzle  from  6  inches  to  one  foot  above  or  from  the  plants.  The 
Saddle  Guns  deliver  chiefly  downward,  and  we  suggest  to  have  the 
nozzle  about  a  foot  above  average  height  of  plants.  The  larger 
(wheel -geared)  machines  deliver  downward  or  horizontal,  and  we 
prefer  the  horizontal  delivery  to  be  about  6  inches  above  average 
height  of  plants. 

All  these  details  are  subject  to  variation.  The  essential  object  is 
to  deliver  a  uniform  cloud  which  (in  the  still  air  with  the  plants 
moist)  will  slowly  settle.  Our  examinations  after  dusting  showed 
the  dust  inside  (under  the  bracts)  of  the  squares.  It  is  not  desired 
to  have  certain  leaves  or  plants  receive  much  heavier  coating  of  dust 
than  others,  hence  the  advantage  of  not  having  the  nozzles  continu¬ 
ally  dragging  on  the  wet  leaves  of  the  plants. 

HOW  TO  POISON  (The  Specific  Guiding  Directions) 

(Adapted  from  U.  S.  Dept.  Agr.  Circular  162,  by  Coad  and  Cassidy.) 

1.  Use  only  pure  calcium  arsenate  in  form  of  dry  powder. 

2.  Apply  this  only  in  the  dust  form. 

3.  Use  only  dusting  machinery  especially  constructed  for  cotton-dusting. 

4.  Dust  only  when  the  air  is  calm  and  the  plants  are  moist.  This  prac¬ 

tically  means  malting  only  night  applications. 

5.  Use  about  5  to  7  pounds  of  calcium  arsenate  per  acre  for  each  applica¬ 

tion. 

6.  Start  poisoning  when  the  weevils  have  punctured  from  10  to  15  per 

cent  of  the  squares. 

7.  Keep  the  cotton  thoroughly  dusted  until  the  weevils  are  under  con¬ 

trol.  This  usually  means  about  three  applications  at  rate  of  one 
every  fourth  night. 

8.  Then  stop  dusting  (poisoning)  until  the  weevils  again  become 

abundant. 

9.  If  the  weevil  again  becomes  abundant  early  enough  to  injure  young 

bolls,  make  one  or  two  more  applications  late  in  the  season. 

10.  If  you  have  a  heavy  rain  within  24  hours  after  dusting,  repeat  the 

application  immediately  (or  that  part  of  it  done  within  the  24 
hours ) . 

11.  Do  not  expect  to  eradicate  the  weevils.  Poisoning  merely  controls 

them  enough  to  get  a  full  crop,  and  you  can  always  find  weevils  in 
the  successfully  poisoned  field. 

12.  Keep  cotton  acreage  low  and  try  to  increase  the  yield  per  acre,  as  it 

costs  as  much  to  poison  one-quarter  bale  per  acre  cotton  as  bale 
per  acre  cotton. 


Dust-Poison  Method  for  Control  of  Boll  Weevil 


21 


13‘  If  you  wish  to  Prove  the  matter  to  yourself,  leave  an  occasional  fair 
average  part  unpoisoned  to  compare  its  yield  with  the  adioinino 
poisoned  part. 

14.  If  you  intend  to  poison,  get  in  touch  with  County  Agent,  or  State 
officials,  or  U.  S.  Delta  Laboratory  at  Tallulah,  La.,  for  any  special 
help  they  may  offer. 

“DO  IT  RIGHT  OR  NOT  AT  ALL” 

Analysis  of  Poison. — The  calcium  arsenate  to  be  used  for  cotton 
dusting  should  analyze  as  follows :  not  less  than  40  per  cent  total  arsenic 
pentoxid — not  more  than  0.75  per  cent  water-soluble  arsenic  pentoxid— 
density  not  less  than  80  or  more  than  100  cubic  inches  per  pound. 

In  former  years  the  United  States  Department  Agriculture  made 
analyses  of  samples,  but  this  is  now  impracticable  and  largely  unneces¬ 
sary,  as  the  manufacturers  have  the  material  fairly  well  standardized. 

TESTS  BY  VIRGINI A-C AROLIN A  CHEMICAL  COMPANY 

Agricultural  Service  Bureau,  A.  E.  Grantham,  Director 

During  1922  this  organization  supervised  tests  of  the  dust-poison 
•method  on  many  farms  in  Uorth  Carolina,  South  Carolina,  Georgia, 
and  Alabama,  and  in  a  booklet  (“Beating  the  Boll  Weevil,”  issued 
December,  1922)  the  results  are  given  for  237  farms  where  the  com¬ 
parative  yields  of  dusted  and  (adjoining)  undusted  cotton  were  secured. 
The  plan  included  in  each  case  5  acres  dusted  and  5  acres  not  dusted. 
In  so  large  a  series,  over  so  wide  territory  (and  with  such  large  plots), 
irregularities  in  land  and  infestation  were  sure  to  occur — and  their 
notes  indicate  this.  In  sotne  of  their  fields  (in  JSTorth  Carolina  also)  the 
infestation  was  light  so  the  gains  were  small.  It  is  probable  also  that 
some  of  the  work  was  better  done,  or  better  timed,  than  in  other  cases. 
Hence  wide  differences  in  the  details  of  the  results  are  not  surprising. 
Their  general  plan  was  much  the  same  as  we  advise  in  the  preceding 
pages. 

When  we  average  their  results  as  secured  in  each  state  we  find  the 
following : 

dust-poison  method,  boll-weevil  control 

Virginia-Carolina  Chemical  Company  Tests,  1922 


• 

State 

Number 

Tests 

Number 

Localities 

Average 
Gain, 
Pounds  of 
Seed  Cotton 
per  Acre, 
by  Dusting 

16 

4 

151 

125 

22 

333 

16 

4 

185 

80 

13 

269 

22 


N.  C.  Agricultural  Extension  Service 


The  general  average  from  all  237  tests,  figured  on  basis  of  one  acre, 


was  as  follows  : 

Dusted  cotton,  lbs.  seed  cotton  per  acre .  857  lbs. 

Not  dusted,  lbs.  seed  cotton  per  acre .  562  lbs. 

Gain — lbs.  seed  cotton  per  acre,  by  dusting .  295  lbs. 


They  figure  the  average  cost  of  dusting  at  $7.20  per  acre,  and  on  this 
basis  the  295  lbs.  seed  cotton  gives  a  substantial  net  profit  above  costs. 

FINAL  REMARKS 

Mr.  B.  R.  Coad,  of  United  States  Bureau  of  Entomology,  stationed  at 
Delta  Laboratory,  Tallulah,  La.,  who  has  been  chiefly  instrumental  in 
developing  the  dust-poison  method,  has  said :  “The  gains  vary  widely, 
but  usually  average  200  to  400  lbs.  seed  cotton  per  acre.”  An  exact 
average  of  the  two  figures  he  mentions  would  be  300  lbs.  It  is  interest¬ 
ing  to  note  that  in  our  own  seven  North  Carolina  tests  (in  1922)  the 
average  gain  was  319  lbs.  seed  cotton  per  acre  (or  305  lbs.  per  acre  for 
the  six  short-staple  tests  only),  and  that  in  the  237  tests  by  the  Yirginia- 
Carolina  Chemical  Company  (in  1922)  the  average  gain  was  295  lbs. 
seed  cotton  per  acre. 

It  therefore  seems  fair  to  regard  300  lbs.  seed  cotton  per  acre  as  a 
good  standard  gain  to  hope  for  from  proper  dusting  when  weevils  are 
rather  abundant.  But  it  is  perhaps  best  to  expect  less  than  we  hope  for, 
and  a  gain  of  200  lbs.  seed  cotton  per  acre  is  gratifying.  Eor,  while 
fluctuations  in  prices  vary  the  case,  it  is  generally  true  that  a  gain  of 
100  lbs.  seed  cotton  per  acre  will  pay  the  cost  of  a  season’s  dusting — 
on  1922  prices  about  75  lbs.  would  have  done  it — we  can  run  into  endless 
calculations  on  costs  and  possible  prices  and  possible  profits  or  losses; 
it  is  not  our  place  to  do  this.  Our  results  of  1922  indicate  a  sound  profit 
from  proper  employment  of  the  dust-poison  method  for  control  of  boll 
weevil. 


- 


FOR  USE  ONLY  IN 

THE  NORTH  CAROLINA  COLLECTION 


UNIVERSITY  OF  N  C  AT  CHAPEL  HILL 


00052876878 


i! 


Form  No.  A-368 ,  Rev.  8/95 


